JPS63270310A - Production of sodium fluoride pellet - Google Patents
Production of sodium fluoride pelletInfo
- Publication number
- JPS63270310A JPS63270310A JP10208287A JP10208287A JPS63270310A JP S63270310 A JPS63270310 A JP S63270310A JP 10208287 A JP10208287 A JP 10208287A JP 10208287 A JP10208287 A JP 10208287A JP S63270310 A JPS63270310 A JP S63270310A
- Authority
- JP
- Japan
- Prior art keywords
- fluoride
- pellets
- sodium fluoride
- potassium fluoride
- sodium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 title claims abstract description 63
- 239000008188 pellet Substances 0.000 title claims abstract description 31
- 239000011775 sodium fluoride Substances 0.000 title claims abstract description 31
- 235000013024 sodium fluoride Nutrition 0.000 title claims abstract description 31
- 238000004519 manufacturing process Methods 0.000 title claims description 12
- NROKBHXJSPEDAR-UHFFFAOYSA-M potassium fluoride Chemical compound [F-].[K+] NROKBHXJSPEDAR-UHFFFAOYSA-M 0.000 claims abstract description 36
- 239000011698 potassium fluoride Substances 0.000 claims abstract description 18
- 235000003270 potassium fluoride Nutrition 0.000 claims abstract description 18
- 238000001035 drying Methods 0.000 claims abstract description 7
- 239000000843 powder Substances 0.000 claims abstract description 6
- 239000000203 mixture Substances 0.000 claims abstract 3
- 238000002156 mixing Methods 0.000 claims description 2
- 239000007864 aqueous solution Substances 0.000 abstract description 7
- 239000011230 binding agent Substances 0.000 abstract description 6
- 238000000034 method Methods 0.000 abstract description 6
- 238000000465 moulding Methods 0.000 abstract description 5
- 239000000126 substance Substances 0.000 abstract description 3
- 230000006835 compression Effects 0.000 abstract 1
- 238000007906 compression Methods 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 15
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 9
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 8
- 229910000040 hydrogen fluoride Inorganic materials 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 238000005245 sintering Methods 0.000 description 5
- 239000003463 adsorbent Substances 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 150000002222 fluorine compounds Chemical class 0.000 description 2
- 239000008187 granular material Substances 0.000 description 2
- MWGKAIKWBCTKHF-UHFFFAOYSA-N C1(=O)OCC2=CC=CC=C12.[Na] Chemical compound C1(=O)OCC2=CC=CC=C12.[Na] MWGKAIKWBCTKHF-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 235000008429 bread Nutrition 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000001784 detoxification Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910001512 metal fluoride Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000005453 pelletization Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000012047 saturated solution Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- SANRKQGLYCLAFE-UHFFFAOYSA-H uranium hexafluoride Chemical compound F[U](F)(F)(F)(F)F SANRKQGLYCLAFE-UHFFFAOYSA-H 0.000 description 1
Abstract
Description
【発明の詳細な説明】
【産業上の利用分野］
本発明は、フッ化物ガス吸Ｍ剤の製造方法に関するもの
であり、さらに詳しくは、フッ化ナトリウムペレットの
製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a fluoride gas absorbing agent, and more particularly to a method for producing sodium fluoride pellets.
【従来の技術］。[Conventional technology].
従来、フッ化ナトリウムはフッ化水素や六フッ化ウラン
等の吸着剤として用いられ、これらのガス等をフッ化ナ
トリウムのペレットを充填した層に通す方法により、除
去する方法が実施されている。この際、充填層中のペレ
ットの圧縮強度が低いと破壊し易く、そのため圧力損失
が大きくなり、ガスの流通が困難となる。このためペレ
ットの圧縮強度を上げるための種々の工夫が行われてい
る０例えば、酸性フッ化ナトリウム粉末をペレット状に
成型し、４００〜５００°Ｃに加熱焼結すると、
Ｎ ａ ＨＦ ２− Ｎ ａ Ｆ 十〇 Ｆなる反応に
よってＮａＦとＨＦに分解し、その後ＨＦを除去するこ
とにより、ある程度強度のあるフッ化ナトリウムペレッ
トが得られる。Conventionally, sodium fluoride has been used as an adsorbent for hydrogen fluoride, uranium hexafluoride, etc., and a method for removing these gases has been carried out by passing these gases through a bed filled with sodium fluoride pellets. At this time, if the compressive strength of the pellets in the packed bed is low, they are likely to break, resulting in a large pressure loss and difficulty in gas flow. For this reason, various efforts have been made to increase the compressive strength of pellets. For example, when acidic sodium fluoride powder is molded into pellets and heated and sintered at 400 to 500°C, N a HF 2-N By decomposing it into NaF and HF by the reaction a F 10 F and then removing HF, sodium fluoride pellets with some strength can be obtained.
また、特開昭５０〜１４５９０号公報には、フッ化ナト
リウムの粉末もしくは顆粒とアルカリ金属および／また
はアルカリ土類金属の粉末もしくは顆粒とを混合成型し
、３００〜６５０°Ｃの温度で２時間以上保持して焼結
する方法により、フッ化ナトリウム単独での焼結より強
度のあるペレットを得ており、特開昭５３−４７９５号
公報には、ステアリン酸マグネシウム等の金属含有滑剤
をフッ化ナトリウムに混合して滑りを良くして、成型を
容易にし、フッ化水素気流中、５００°で焼成して、金
属含有滑剤を金属フッ化物に変えることにより、強度の
あるフッ化ナトリウムペレットを得る方法が知られてい
る。Furthermore, in JP-A-50-14590, powders or granules of sodium fluoride and powders or granules of alkali metals and/or alkaline earth metals are mixed and molded at a temperature of 300 to 650°C for 2 hours. By the above method of holding and sintering, pellets with stronger strength than those obtained by sintering with sodium fluoride alone have been obtained. Mixed with sodium to improve slippage and facilitate molding, and baked at 500° in a stream of hydrogen fluoride to change the metal-containing lubricant to metal fluoride to obtain strong sodium fluoride pellets. method is known.
さらには、リムド綱の脱ガス剤として主に用いられてい
るもので、有機物例えばゴム等をバインダーとして造粒
したフッ化ナトリウムペレット等が知られ°ζいる。Furthermore, sodium fluoride pellets, etc., which are granulated using an organic substance such as rubber as a binder, are mainly used as a degassing agent for Limdo class.
［本発明が解決しようとする問題点１
前述した例の中で、ＮａＨＦｚの分解を利用する場合は
、２００°Ｃ以上でフッ化水素ガスが発生するため、特
殊な装置を用いなければならず、加えて脱離したフッ化
水素の回収、除害といった操作が必要であり、製造工程
が複雑となる。[Problem 1 to be solved by the present invention In the above-mentioned example, when using decomposition of NaHFz, hydrogen fluoride gas is generated at temperatures above 200°C, so special equipment must be used. In addition, operations such as recovery and detoxification of desorbed hydrogen fluoride are required, which complicates the manufacturing process.
また、脱ＨＦ後４００°Ｃ以上と言う高温で焼結するこ
とでペレットの強度の向上を計っているがこのため製造
コストが非常に高くなる。In addition, the strength of the pellets is improved by sintering them at a high temperature of 400° C. or higher after removing HF, but this makes the manufacturing cost extremely high.
一方、特開昭５０−１４５９０号公報、および特開昭５
３−４７９５号公報の例では、フッ化水素ガスが発生す
るという欠点は改善されているが、やはりペレットの焼
結温度が３００〜６５０°Ｃと高いため、製造コストが
高（なる。On the other hand, JP-A-50-14590 and JP-A-5
In the example of Publication No. 3-4795, the disadvantage of generation of hydrogen fluoride gas has been improved, but the sintering temperature of the pellets is still as high as 300 to 650°C, resulting in high manufacturing costs.
また、バインダー使用によるペレットをフッ化物ガスの
吸着剤として用いる場合、バインダーのゴムとフッ化物
ガスが反応し、ペレットの圧縮強度の劣化等の問題があ
る。このように、従来のフッ化ナトリウムペレットを、
フッ化物ガスの吸着剤として工業的に用いる場合、経済
的にまた性能的に改善の余地があった。Further, when pellets using a binder are used as an adsorbent for fluoride gas, the rubber of the binder and the fluoride gas react with each other, causing problems such as deterioration of the compressive strength of the pellets. In this way, conventional sodium fluoride pellets can be
When used industrially as an adsorbent for fluoride gas, there is room for improvement economically and in terms of performance.
［問題を解決するための手段］
本発明は、かかる問題を解決すべく鋭意検討を行った結
果、本発明に到達したものである。[Means for Solving the Problems] The present invention was achieved as a result of intensive studies to solve these problems.
すなわち本発明は、粉末のフタ化ナトリウムとフッ化カ
リウム水溶液を混合した後、成形機によりペレット状に
成形し、これを１００”Ｃ以上で乾燥することにより、
フッ化ナトリウム粒子間で可溶性フッ化物を再結晶させ
ることで、より圧縮強度の高いフッ化ナトリウムペレッ
トを製造する方法を見いだした。このようにフッ化カリ
ウムの再結晶物質をバインダーとすることにより従来の
製造方法のように、２００°Ｃ以上でフッ化水素を除去
する必要はなくなり、また４００°Ｃ以上で焼結すると
いう操作を必要とせず十分圧検強度のあるフッ化ナトリ
ウムペレットを得ることができる。That is, in the present invention, after mixing powdered sodium phthalide and potassium fluoride aqueous solution, the pellets are formed using a molding machine, and the pellets are dried at 100"C or higher.
We have discovered a method for producing sodium fluoride pellets with higher compressive strength by recrystallizing soluble fluoride between sodium fluoride particles. By using recrystallized potassium fluoride as a binder, it is no longer necessary to remove hydrogen fluoride at temperatures above 200°C, as in conventional manufacturing methods, and the process of sintering at temperatures above 400°C is eliminated. Sodium fluoride pellets with sufficient pressure test strength can be obtained without the need for
本発明でフッ化カリウムを選択した理由は、水に対して
適当な溶解度をもつていること、３００°Ｃ以下で、容
易に結晶水を放出、無水物となること、安価であること
、フッ化物ガスの吸着剤として用いる場合、吸着するガ
スに対して安定であること、という諸条件を満足するた
めであり、そのため種々の化合物について、検討を行っ
た結果、次Ｈ第１表の飽和水溶液１００ｇ中に含まれる
フッ化物の重量からもわかるようにフッ化カリウムが最
も好ましい化合物であることを見い出した。 このよう
に、フッ化カリウムはフッ化物の中でも特に水に対する
溶解度が高いためバインダー効果が大きく、他のフッ化
物は水にほとんど溶解しないので、強度が上がらず不適
当である。The reasons why potassium fluoride was selected in the present invention are that it has appropriate solubility in water, that it easily releases crystal water below 300°C, becomes anhydrous, that it is inexpensive, and that potassium fluoride When used as an adsorbent for chemical gases, the purpose is to satisfy the various conditions of being stable to the gas to be adsorbed.For this reason, after studying various compounds, we found that the saturated aqueous solutions shown in Table 1 below. As can be seen from the weight of fluoride contained in 100 g, potassium fluoride was found to be the most preferable compound. As described above, potassium fluoride has a particularly high solubility in water among fluorides, so it has a large binder effect, while other fluorides hardly dissolve in water, so they do not increase strength and are therefore unsuitable.
第１表
本発明でもちいるフッ化カリウム水溶液は、水酸化カリ
ウムにソツ化水素水溶液を当量添加することにより、容
易に得ることができる。Table 1 The potassium fluoride aqueous solution used in the present invention can be easily obtained by adding an equivalent amount of a hydrogen fluoride aqueous solution to potassium hydroxide.
また、粉末フッ化ナトリウムにｔト加する可溶性フッ化
物水溶液の量は、少ないと成型機によリペレソト状にす
るとき成型しに＜＜、多いと乾燥時間が長くなるため、
好ましくは、粉末フッ化ナトリウムに対し３重重％から
２０重１％がよい、 ペレット化する方法としては、通
常の傳留装置例えば、ドラム型、パン型、タプレントマ
シーン等のものが使用できる。このようにして製造した
フッ化ナトリウムペレットは、製造工程も日型であり、
非常に安価に使用することができ工業的に用いる場合有
利である。In addition, if the amount of soluble fluoride aqueous solution added to powdered sodium fluoride is small, it will be difficult to mold it into a shape using a molding machine, and if it is large, the drying time will be longer.
Preferably, the amount is from 3% by weight to 20% by weight based on powdered sodium fluoride.As a method for pelletizing, a conventional extrusion device such as a drum type, bread type, taplant machine, etc. can be used. The manufacturing process of the sodium fluoride pellets manufactured in this way is also the Japanese type,
It can be used at a very low cost and is advantageous for industrial use.
以下実施例により本発明をさらに詳しく説明する。The present invention will be explained in more detail with reference to Examples below.
［実施例］
実施例１
フ・ン化カリウムの飽和溶液を用い粉末のフッ化ナトリ
ウムに対し、それぞれ５重量％、１０重重量、１５重１
％添加し均一に混合した後５、クプレットマシーンによ
り直径５１Ｉのベレット状にしたものを、１５０°で１
０時間乾燥し、各ペレットの圧縮強度を測定した。なお
比較例としてフッ化ナトリウム飽和溶液を用いた。その
結果を第２表に示すが、この結果よりわかるように、水
に対する飽和溶解度の大きいフッ化カリウムの水γ′ａ
液を添加したフッ化ナトリウムペレットは圧縮強度が大
きく１−公吏用可能である。[Example] Example 1 Using a saturated solution of potassium fluoride, 5% by weight, 10% by weight, and 15% by weight, respectively, were added to powdered sodium fluoride.
% was added and mixed uniformly, and then made into a pellet shape with a diameter of 51I using a cuplet machine.
After drying for 0 hours, the compressive strength of each pellet was measured. Note that a saturated sodium fluoride solution was used as a comparative example. The results are shown in Table 2. As can be seen from the results, potassium fluoride has a high saturation solubility in water, γ'a
Sodium fluoride pellets with added liquid have high compressive strength and can be used for public officials.
実施例２
実施例１と同様にフッ化カリウム水Ｒｉ＆を用い４度、
乾燥温度の条件を変え、また実施例１と同様にペレット
を作り、圧縮強度を測定したその結果を第３表に示す、
この結果よりわかるように、フッ（ヒナトリウムに対す
るフッ化カリウムの添加量が多く、１００〜３００°で
乾燥すれば、圧８１強度の大きいフッ化ナトリウムペレ
ットを１′：４ることができる。囚にフッ化ナトリウム
に対して、可溶性フッ化物水７８液の積が３０重盟％を
超えると成形しにくり、乾燥時間も長（なる。Example 2 Similar to Example 1, using potassium fluoride water Ri & 4 times,
Pellets were made in the same manner as in Example 1, with different drying temperature conditions, and the compressive strength was measured. The results are shown in Table 3.
As can be seen from this result, if the amount of potassium fluoride added to the sodium fluoride is large and dried at 100 to 300°, sodium fluoride pellets with a high pressure 81 strength can be obtained at a ratio of 1':4. If the product of sodium fluoride and 78 parts of soluble fluoride water exceeds 30% by weight, molding becomes difficult and the drying time becomes long.
実施例３
フッ化ナトリウム１Ｋｇと、フッ化カリウム５０重量％
水ｔ８ｆｉＯ，ＩＫｇを）昆合し、成形したペレットを
、１５０°Ｃ１１０時間乾燥したもののフッ化物ガスに
対する吸着能力を測定した。 吸着ガス濃度は１０ｖｏ
ｌｚ／Ｎ ２であり、ガスを１１／ｓｉｎで流して５時
間後の重量増加をガス吸着能力とした。その結果を第４
表に示す。Example 3 1Kg of sodium fluoride and 50% by weight of potassium fluoride
The adsorption ability for fluoride gas was measured by combining t8fiO, Ikg of water, forming pellets, and drying them at 150°C for 110 hours. Adsorbed gas concentration is 10vo
lz/N 2 , and the weight increase after 5 hours of gas flow at 11/sin was defined as the gas adsorption capacity. The result is the fourth
Shown in the table.
第２表
注）粉末ＮａＦの重！１．０ｋｇ
第３人
第１１表
［発明の効果］
以上のように、本発明により得られたフッ化ナトリウム
ベレットは、従来のように２００°Ｃ以上でフッ化水素
を取り扱う必要がなく、また４００″Ｃ以上で焼結する
必要もないので、装置の材質、製造工程の面から考える
と、製造コストが非常に安価で且つ安全であり、また圧
縮強度、吸着強度の優れたものとなる。Table 2 Note) Weight of powdered NaF! 1.0kg Third Person Table 11 [Effects of the Invention] As described above, the sodium fluoride pellets obtained by the present invention do not require handling hydrogen fluoride at 200°C or higher as in the past, and Since there is no need to sinter at temperatures above 400''C, the manufacturing cost is very low and safe in terms of the material of the device and the manufacturing process, and it also has excellent compressive strength and adsorption strength.
Claims (1)
し、ペレットに成形後乾燥し、フッ化カリウムを再結晶
させることを特徴とするフッ化ナトリウムペレットの製
造方法。A method for producing sodium fluoride pellets, which comprises mixing sodium fluoride powder and an aqueous potassium fluoride solution, forming the mixture into pellets, drying the mixture, and recrystallizing the potassium fluoride.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10208287A JPS63270310A (en) | 1987-04-27 | 1987-04-27 | Production of sodium fluoride pellet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10208287A JPS63270310A (en) | 1987-04-27 | 1987-04-27 | Production of sodium fluoride pellet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63270310A true JPS63270310A (en) | 1988-11-08 |
Family
ID=14317854
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10208287A Pending JPS63270310A (en) | 1987-04-27 | 1987-04-27 | Production of sodium fluoride pellet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63270310A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998026855A1 (en) * | 1996-12-19 | 1998-06-25 | British Nuclear Fuels Plc | Method for preparing alkali metal fluoride pellets and gas scrubbing method using the same |
| KR20170131688A (en) | 2016-04-01 | 2017-11-29 | 사사키카가쿠야쿠힌 가부시키가이샤 | Alkali metal salt-containing molded article and method for regenerating acidic aqueous solution using the same |
-
1987
- 1987-04-27 JP JP10208287A patent/JPS63270310A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1998026855A1 (en) * | 1996-12-19 | 1998-06-25 | British Nuclear Fuels Plc | Method for preparing alkali metal fluoride pellets and gas scrubbing method using the same |
| KR20170131688A (en) | 2016-04-01 | 2017-11-29 | 사사키카가쿠야쿠힌 가부시키가이샤 | Alkali metal salt-containing molded article and method for regenerating acidic aqueous solution using the same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5670445A (en) | Cleaning agent of harmful gas and cleaning method | |
| JPS6040893B2 (en) | Ethylene absorbent and its manufacturing method | |
| JPH04222629A (en) | Metal oxide co2 solvent able to be regenerated and its manufacture and use | |
| JPS63270310A (en) | Production of sodium fluoride pellet | |
| TW524720B (en) | Cleaning agent for hazardous gas | |
| JP3571095B2 (en) | Method for producing acid gas absorbent | |
| CN109589780B (en) | Hydrogen fluoride gas adsorbent and preparation method thereof | |
| JP4051399B2 (en) | Desiccant raw material and production method thereof | |
| JP3701741B2 (en) | Hazardous gas purification agent | |
| JPH02144125A (en) | Method for purifying exhaust gas | |
| JPH01180222A (en) | Production of molded body for cleaning up exhaust gas | |
| JPH0673613B2 (en) | Exhaust gas purification method | |
| JP3362918B2 (en) | Exhaust gas purification method | |
| JPH04190847A (en) | Agent for removing tetrachloroethylene in water and preparation thereof | |
| JP2008302338A (en) | Detoxifying agent for metal hydride-containing exhaust gas, and detoxifying method for metal hydride-containing exhaust gas | |
| JPH0313186B2 (en) | ||
| JPS62286520A (en) | Method for purifying exhaust gas | |
| JP2001190965A (en) | Purifying agent for poisonous gas and purification method | |
| JP3330500B2 (en) | Nitrogen trifluoride gas abatement agent and abatement method | |
| JPS6071039A (en) | Noxious gas adsorbent | |
| JPH07155541A (en) | Harmful effect removing agent for gaseous nitrogen trifluoride | |
| JPH08206185A (en) | Deodorant | |
| RU2339444C2 (en) | Method of sorbent production | |
| JPH04326940A (en) | Catalyst for decomposition of ozone | |
| JPH0616402A (en) | Method for refining nitrous oxide |